JPH0623018Y2 - Printed circuit board joint structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a printed circuit board joint structure in which one of two printed circuit boards is inserted into the other to solder the electrode patterns of the two printed boards.

[Conventional technology]

FIG. 6 is a perspective view showing an example of a conventional printed circuit board joining structure.

Reference numeral 2 denotes a first printed circuit board (for example, a sub printed circuit board) on which required electronic components are mounted (not shown),
Moreover, one or more electrode patterns 6 are extended on one surface of the tongue piece portion 4 and a land portion 8 for soldering is provided on each of them.

Reference numeral 12 denotes a second printed circuit board (for example, a main printed circuit board), on which necessary electronic components are mounted (not shown), and in the peripheral portion of the hole 14 that fits with the tongue piece portion 4, On the back surface side, the electrode patterns 16 are extended so as to correspond to the respective land portions 8 and, in this example, land portions 18 for soldering are respectively provided.

Then, the tongue piece 4 of the first printed circuit board 2 is inserted into the hole 14 of the second printed circuit board 12, and the corresponding land parts 8 and 18 of both printed circuit boards 2 and 12 are soldered to each other. Thereby, the two printed boards 2 and 12 are joined together.

[Problems to be solved by the device]

In this case, if attention is paid to the first printed circuit board 2 side here, it is necessary to solder between the electronic component mounted on the first printed circuit board 2 and the electrode pattern before joining as described above.
For this purpose, generally, for automation or the like, immersion soldering is used in which the joint surface is immersed in a molten solder bath.

However, in this case, as shown in FIG. 7, for example, the solder 10 also adheres to the land portion 8 of the tongue piece portion 4 at the same time.
The total thickness T of the tongue piece 4 of the printed circuit board 2 including the solder 10 may be larger than the width W of the hole 14 of the printed circuit board 12, which may make it impossible to insert the printed circuit board 2. .

By the way, in such a case, it is necessary to remove the solder 10 attached to the land portion 8 of the printed circuit board 2 by a separate process, which lowers the workability of the assembly and causes heat when removing the solder 10. There is a risk that the reliability of the product will decrease due to the adverse effect.

Then, this invention aims at providing the joining structure of the printed circuit board which improved such a point.

[Means for Solving the Problems]

The printed circuit board joint structure of the present invention is characterized in that each land portion of the first printed circuit board as described above is partially provided with a region for preventing solder adhesion.

[Action]

By partially providing each land portion with a region that hinders solder adhesion, the amount of solder adhesion to each land portion is reduced and the solder rise is reduced. Therefore, for example, even when the tongue piece is inserted into the hole of the second printed circuit board after the first printed circuit board is dipped and soldered, the swelling of the solder in each land part may make the insertion impossible. Can be prevented.

〔Example〕

1 to 5 are enlarged front views each showing one land portion of the first printed circuit board in the printed circuit board joining structure according to the embodiment. The same parts as those in the examples of FIGS. 6 and 7 are designated by the same reference numerals, and the differences from the conventional example will be mainly described below.

In the embodiment shown in FIG. 1, a round hole 3 is provided as an example of a region for preventing solder adhesion in each land portion 28 corresponding to the land portion 8 in the tongue piece portion 4 of the first printed circuit board 2 as described above.
There are some 0s.

In the example of FIG. 2, some slits 31 are formed in the land portion 28.

In this case, as a general rule, the solder is not placed on the holes 30 and the slits 31, so that the amount of solder adhered to each land 28 is reduced and the rise of the solder is reduced.

Therefore, for example, even when the tongue piece portion 4 is inserted into the hole 14 of the second printed circuit board 12 as described above after the printed circuit board 2 is immersed and soldered, each land portion 2
It is possible to prevent a situation in which the insertion becomes impossible due to the rise of the solder in 8.

As a result, unlike the conventional example, it is not necessary to remove the solder of the land portion 28 by a separate process, so that the workability of assembly is improved and the reliability of the product is improved because it is not adversely affected by heat at that time.

The shape, means, etc. of the area for preventing the solder from being attached to each land portion 28 are the holes 30 and the slits 3 as in the above example.
Various other than 1 can be adopted.

For example, as shown in FIG. 3, when the printed circuit board 2 is moved as indicated by an arrow in dipping and soldering, if the slit 32 is provided along the moving direction, the pool of the solder is reduced, so that the land portion is reduced. The solder rise at 28 is smaller.

In the same case as above, for example, as shown in FIG.
The same effect can be obtained by placing the slits 33 on the rear side of the land portion 28 where solder is likely to accumulate.

In addition, the holes 30 and the slits 3 as described above are formed in the land portion 28.
Instead of providing 1 to 33, a solder resist may be attached on each land portion 28 in the same pattern as those.

FIG. 5 shows an example of such a solder resist film which prevents solder adhesion so that the electrode 28e is exposed in a comb shape on the electrode pattern 6 as described above and on the land portion 28 at the tip thereof. 34 is covered.

In addition, the land portion 28 provided on the tongue portion 4 of the printed circuit board 2
The shape and the number of itself are not necessarily limited to those in the above example, and various ones can be adopted.

[Effect of device]

As described above, according to the present invention, each land portion of the first printed circuit board is partially provided with a region that hinders solder adhesion, so that the amount of solder adhesion to each land portion is reduced and the solder rise is small. Become. Therefore, for example, even when the tongue piece is inserted into the hole of the second printed circuit board after the first printed circuit board is immersed and soldered,
It is possible to prevent the possibility that the insertion becomes impossible due to the rise of the solder in each land portion.

[Brief description of drawings]

1 to 5 are enlarged front views each showing one land portion of the first printed circuit board in the printed circuit board joining structure according to the embodiment. FIG. 6 is a perspective view showing an example of a conventional printed circuit board joining structure. 7th
The drawing is a side view showing the insertion portion of FIG. 6 in an enlarged manner. 2 ... first printed circuit board, 4 ... tongue portion, 6, 16 ...
... Electrode pattern, 8, 18, 28 ... Land portion, 10 ...
... solder, 12 ... second printed circuit board, 14 ... hole, 3
0 ... hole, 31-33 ... slit, 34 ... solder resist film.

Claims (1)

[Scope of utility model registration request] 1. A tongue portion of a first printed circuit board, wherein one or more electrode patterns are extended on the tongue portion and solder land portions are provided on the tongue portion. In the joint structure of the printed circuit board, the electrode pattern is inserted into the corresponding hole of the second printed circuit board, and the corresponding land portions of both printed circuit boards and the electrode patterns are soldered to each other. A joint structure of a printed circuit board, characterized in that each land portion of the first printed circuit board is partially provided with a region for preventing solder adhesion.